<!DOCTYPE html>
<html lang="en">

    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Document</title>
        <style type="text/css">
            body { margin: 0 ; padding: 0 ; }
            .outer { border : 1px solid blue ; border-collapse: collapse ; width: 100% ; }
            .outer tr td { border : 1px solid blue ; }
            .header>td { height: 50px ; }
            .middle>td { height: 700px ; }
            .footer>td { height: 50px ; }
        </style>
    </head>

    <body>

        <table class="outer">
            <tr class="header">
                <td width="50%">
                    <!-- 在 td 内部可以插入另外一个表格 -->
                    <table>
                        <tr>
                            <td>新闻</td>
                            <td>hao123</td>
                            <td>地图</td>
                            <td>视频</td>
                            <td>贴吧</td>
                            <td>学术</td>
                            <td>更多</td>
                        </tr>
                    </table>

                </td>
                <td width="50%"></td>
            </tr>
            <tr class="middle">
                <td colspan="2" align="center" valign="middle" >
                    
                    <table> <!-- 嵌套表格开始 -->
                        <tr>
                            <td colspan="2">
                                <img src="bd.png" width="270">
                            </td>
                        </tr>
                        <tr>
                            <td>
                                <input type="text" name="wd">
                            </td>
                            <td>
                                <input type="submit" value="提交">
                            </td>
                        </tr>
                    </table> <!-- 嵌套表格结束 -->

                </td>
            </tr>
            <tr class="footer">
                <td></td>
                <td></td>
            </tr>
        </table>

    </body>

</html>